Cancer prevention
=================

* Janusz Jankowski
* Emma Boulton

## Introduction

A 44 year old woman attends your surgery, distressed by the fact that her closest friend has just been given a diagnosis of colorectal cancer. She wants to know how to minimise her risk of developing cancer.

## What issues you should cover

*Initial feelings and attitudes*—What are her ideas, concerns, and expectations with regard to her friend's diagnosis?

*Risk assessment for colorectal or other cancer*—Does she have any risk factors for colorectal cancer? (See box.) Cover other important causes of cancer generally. Many risk factors relate to lifestyle (diet, physical activity, smoking), and cancer prevention overlaps with prevention of other diseases, such as vascular disease. *Outline the basic facts*—Reassure her that most patients treated for cancer today don't die from the disease, that at least half of these patients are cured, and that less than a third of the population develop any form of cancer in their lifetime. However, mention that gastrointestinal tumours account for a quarter of all cases of cancer, the majority of which are caused by factors that could have been avoided through lifestyle modification. In adults only a fifth of cancers develop before the age of 45, usually only those strongly linked to hereditary factors, whereas most cancers occur mainly in the sixth, seventh, and eighth decades of life.

*Explore her level of understanding, expectations, and beliefs*—Can she identify her risk factors for developing malignancy? Does she understand which risk factors for cancer are modifiable and which aren't? How is she going to change her behaviour?

#### A to K of factors associated with specific cancer sites: an empirical basis for recommending lifestyle changes

**A**lcohol consumption > 3 units a day: most squamous cancers, especially bladder and oesophagus

**B**ody mass index > 25 and certainly > 30: all solid cancers

**C**igarette smoking at any level (even passive smoking): bladder, lung, head and neck, oesophagus, and oropharyngeal cancers

**D**iet, especially one that is high in fat: all solid cancers

**E**xercising < 30 minutes a day: all solid cancers

**F**amily history of cancer (in at least one first degree relative and at least three people in two or more generations): inherited cancer syndromes, including breast, colorectal, diffuse gastric, ovarian, prostate, and uterine cancers

**G**enital and sexual health (sexually transmitted infections): cervical cancer

**H**ealth promoting drugs that may decrease global cancer risks (but need a careful risk benefit analysis): colonic adenomas can be treated with low dose aspirin but can have serious side effects; hormone replacement therapy is linked with breast cancer

**I**ntense sunburn: melanoma

**J**ob related factors: lung cancer (exposure to asbestos and particulates), skin cancer (contact with arsenic)

**K**nown disease associations: colorectal cancer has predisposing mucosal pathology—adenomas, coeliac disease, ulcerative colitis

#### Useful websites for patients

NHS cancer screening programmes:

[www.cancerscreening.nhs.uk/](http://www.cancerscreening.nhs.uk/)

CancerBACUP (the UK's leading cancer information service):

[www.cancerbacup.org.uk/](http://www.cancerbacup.org.uk/)

Cancer Research UK: [www.cancerresearch.org.uk/](http://www.cancerresearch.org.uk/)

## What you should do

*   Briefly check that she has no physical symptoms that may warrant further investigation, such as bleeding in the rectum, altered bowel habit, or weight loss. If the history is unremarkable you can move on to focus on cancer prevention.

*   Gather basic health information, such as her body mass index, smoking status, level of exercise, and personal and family history.

*   Caution her that although early investigation of cancer symptoms increases the chances of any cancer being successfully treated, alarm symptoms for cancer vary in their sensitivity and specificity.

*   Emphasise the importance of a good diet. She should eat at least five portions of fruit and vegetables each day and cut down on fat, salt, and added sugar.

*   Explain that many cancers are preventable through lifestyle modification, and help her decide what to tackle first: smoking, exercise, dietary modification, or alcohol consumption.

*   Cancer prevention and lifestyle modification need ongoing support, so you should arrange for review either with you or a practice nurse.

*   Balance the risks of medical interventions such as radiography, cytology, and endoscopy with those of screening programmes for breast, cervical, and colorectal cancer. Most patients asking about the risk of cancer won't develop it, and in about 10% of people anxiety levels will be raised needlessly.

*   Give her written information, such as useful websites and details of support groups for cancer patients and their carers.

#### Useful reading

Austoker J. *Cancer prevention in primary care*. London: BMJ Books, 1995

Hobbs R, Kerr DJ, Young AM. *ABC of colorectal cancer*. London: BMJ Books, 2001

Key TJ, Scatzkin A, Willett WC, Allen NE, Spencer EA, Travis RC. Diet, nutrition and the prevention of cancer. *Pub Health Nutr* 2004;7: 187–200

## Footnotes

*   **This is part of a series of occasional articles on common problems in primary care**

*   The series is edited by general practitioners Ann McPherson and Deborah Waller (ann.mcpherson{at}dphpc.ox.ac.uk) The *BMJ* welcomes contributions from general practitioners to the series

*   We thank Tim Key and David Kerr, Oxford University, and Alex Markham, Cancer Research UK, for their helpful comments.

*   Funding Cancer Research UK, the National Cancer Research Institute, and the National Translational Research Network